This section provides background information related to the present invention, which is not necessarily prior art.
Concomitant with generalization of wide use of various mobile terminals, and commercialization of wireless internet services, demands by consumers related to mobile terminals are also diversified to allow various types of peripheral devices to be mounted on the mobile terminals.
Among the representative items thereof, a camera module photographing a subject in a picture or a video may be mentioned. Meantime, a camera module equipped with auto focus function is recently used. Furthermore, a camera module equipped with auto focus feedback function has been developed. Meantime, in order to implement the abovementioned auto focus feedback function, there is a need to accurately detect a movement of bobbin mounted with a lens to an optical axis direction.
However, the conventional camera module suffers from disadvantages in that an optical axis direction position of a sensor is changed in response to a coated mount of adhesive in the manufacturing process. Furthermore, the conventional camera module suffers from disadvantages in that an optical axis direction position of a sensing magnet is changed in response to a coated mount of adhesive in the manufacturing process.
Meantime, in order to realize the abovementioned auto focus function and auto focus feedback function, there is a need to supply an electric power to a driving part moving a lens and to electrically connect a lens movement-sensing sensor to an outside element.
However, the convention lens driving device suffers from disadvantages in that peaks and workability deteriorate in the coupling between conductive members for forming a conductive line for a driving part and a sensor.
Furthermore, the convention lens driving device suffers from disadvantages in that operation defects occur due to disengaged coupling after reliability test because coupling between conductive members for forming a conductive line for a driving part and a sensor is not properly implemented.
A camera module for miniaturization and low power consumption is difficult in being applied with a VCM (Voice Coil Motor) used in the conventional camera module and therefore, studies thereto are being briskly waged. Demands and manufacturing increase for smart phones and electronic products such as portable phones mounted with a camera. Trends are that a camera for portable phones is being high-pixelated and miniaturized and an actuator is also miniaturized, large-calibered and multi-functionalized in response to the abovementioned trend.
Concomitant with miniaturization and slimming of cameras for mobile phones, an electromagnetic force of a lens driving device for camera module decreases and spring force of an elastic member also decreases. Moreover, the vibration motor for mobile phones is also changed in shape to a linear vibration motor due to increased capacity of battery for mobile phones in order to allow a vibration motor for vibration mode of a mobile phone disposed at a lower side of a battery to be disposed near to a camera module and to make vibration feel good.
The linear vibration motor suffers from disadvantages in that resolution of a camera mounted on the mobile phone may deteriorate due to influence from vibration as the vibration is generated to an optical axis direction of a lens driving device, and noise may be generated.
Furthermore, an outside shock, e.g., a shock generated during touch input of a smart phone may result in generation of trembling on the lens driving device mounted on the mobile phones, and the resolution of a camera may deteriorate due to the trembling.